Re: [sympy] Test failure in 0.7.0 pysics.quantum.matrixcache

Mon, 20 Jun 2011 17:07:18 -0700

Thanks for investigating, Aaron. Maybe numpy importing should be pulled out into its own module. This would probably be necessary anyway if someone implements the "numpy array for sympy" idea that was talked about a while back. 

Ted

On 2011-06-20, at 00:42, Aaron Meurer wrote:


The way the quantum code is written, it's not very easy to disable
numpy globally.  I could do it, but it would require copying the same
four lines checking the system version and emitting a warning in the
half dozen files that import numpy.

So, to fix this right, I need advice from Brian and others who know
the quantum code.  Where would be the best place to put some kind of
global parameter defining if numpy is supported for the quantum code
(similar to what the polys use for gmpy)?

Aaron Meurer
On Sun, Jun 19, 2011 at 8:38 PM, Aaron Meurer <[email protected]> wrote: 
OK, this is definitely a bug in numpy (or Python).  I created a file
numpyfloattest.py with the following contents:

import numpy

class A(object):
   def __float__(self):
       return 2.0
   def __complex__(self):
       return 5.0j

a = A()

print numpy.matrix([[a]], dtype='complex')

And ran:

Aaron-Meurer:sympy aaronmeurer(0.7.0$%)$python2.5 numpyfloattest.py
[[ 2.+0.j]]
Aaron-Meurer:sympy aaronmeurer(0.7.0$%)$python2.7 numpyfloattest.py
[[ 0.+5.j]]

So for some reason, in Python 2.5, it runs complex(float()) on the
data.  Of course, this doesn't work very well if the numbers are
complex, like sympy.I.

I have created http://projects.scipy.org/numpy/ticket/1872 for this.
In the meanwhile, I will just disable numpy in the quantum code in
Python 2.5.

Aaron Meurer
On Sun, Jun 19, 2011 at 8:04 PM, Aaron Meurer <[email protected]> wrote: 
I think I have a lead.  In numpy 1.6, this instead gives


numpy.matrix([[0, I]], dtype='complex')

Traceback (most recent call last):
 File "<stdin>", line 1, in <module>
File "/Library/Frameworks/Python.framework/Versions/2.5/lib/ python2.5/site-packages/numpy/matrixlib/defmatrix.py", 
line 257, in __new__
   arr = N.array(data, dtype=dtype, copy=copy)
 File "sympy/core/expr.py", line 129, in __float__
   raise ValueError("Symbolic value, can't compute")
ValueError: Symbolic value, can't compute

in Python 2.5 (and it works in Python 2.6 and 2.7).  So I guess the
bug is in SymPy somewhere, and numpy 1.5 was catching that ValueError 
and re-throwing it as a TypeError.

Aaron Meurer
On Sun, Jun 19, 2011 at 7:39 PM, Aaron Meurer <[email protected]> wrote:
On Sun, Jun 19, 2011 at 7:32 PM, Aaron Meurer <[email protected]> wrote:
I don't know much about numpy, so this one has me stumped. For some 
reason numpy.matrix([[0, I]], dtype='complex') fails in Python 2.5
(with the above error), but not in Python 2.6 or 2.7 (I is sympy.I).
Can someone with numpy knowledge give any insight here? Otherwise, I think the solution might have to be to disable numpy support in the 
quantum code in Python 2.5.
I haven't looked at why it kills the test runner yet. I'll look at that now.
Oh, this is rather obvious. It's because the exception is raised at import time. If it were raised when running an actual test, it would be caught by the test runner. This is probably OK behavior (anyway, 
it's not top priority to change it).

Aaron Meurer
By the way, a workaround might be to do np.matrix([map(complex, i) for i in m.tolist()], dtype=complex), i.e., manually convert the elements 
of the Matrix to complex, but this is rather hackish and I would
prefer to aviod it if possible.

Aaron Meurer
On Sun, Jun 19, 2011 at 5:36 PM, Aaron Meurer <[email protected]> wrote:
Thanks for reporting this. It seems you've uncovered two bugs (the 
second one is that the error killed the test runner).
I'll see if I can figure out how to fix at least the numpy one for the 
release.  Do you know how to fix it?  If so, please send a pull
request.

Aaron Meurer
On Sat, Jun 18, 2011 at 1:03 PM, Ted Horst <[email protected] > wrote:
I'm a little late to the party, but I just tested 0.7.0 tip and got this 
error (stopped testing):
This is with python 2.5.1, numpy 1.5.0, no scipy, no gmpy on OSX 10.5.8 PPC 
(big endian).
I can get the error from just importing sympy.physics.quantum.matrixcache. It makes sense because we are passing sympy.I with dtype 'complex' to 
numpy.

Ted

Traceback (most recent call last):
 File "setup.py", line 269, in <module>
   'audit' : audit,
 File
"/System/Library/Frameworks/Python.framework/Versions/2.5/lib/ python2.5/distutils/core.py", 
line 151, in setup
   dist.run_commands()
 File
"/System/Library/Frameworks/Python.framework/Versions/2.5/lib/ python2.5/distutils/dist.py", 
line 974, in run_commands
   self.run_command(cmd)
 File
"/System/Library/Frameworks/Python.framework/Versions/2.5/lib/ python2.5/distutils/dist.py", 
line 994, in run_command
   cmd_obj.run()
 File "setup.py", line 161, in run
   if sympy.test():
 File "sympy/utilities/runtests.py", line 181, in test
   return t.test(sort=sort)
 File "sympy/utilities/runtests.py", line 487, in test
   self.test_file(f)
 File "sympy/utilities/runtests.py", line 499, in test_file
   execfile(filename, gl)
 File
"/users/ted/developer/opensource/sympy/sympy_github2/sympy/ physics/quantum/tests/test_gate.py", 
line 4, in <module>
   from sympy.physics.quantum.gate import (XGate, YGate, ZGate,
random_circuit,
 File "sympy/physics/quantum/gate.py", line 31, in <module>
   from sympy.physics.quantum.matrixcache import matrix_cache
File "sympy/physics/quantum/matrixcache.py", line 92, in <module> 
   matrix_cache.cache_matrix('Y', Matrix([[0, -I], [I, 0]]))
File "sympy/physics/quantum/matrixcache.py", line 38, in cache_matrix 
   self._numpy_matrix(name, m)
File "sympy/physics/quantum/matrixcache.py", line 72, in _numpy_matrix 
   m = to_numpy(m, dtype=self.dtype)
File "sympy/physics/quantum/matrixutils.py", line 99, in to_numpy 
   return sympy_to_numpy(m, dtype=dtype)
File "sympy/physics/quantum/matrixutils.py", line 53, in sympy_to_numpy 
   return np.matrix(m.tolist(), dtype=dtype)
 File "numpy/matrixlib/defmatrix.py", line 257, in __new__
TypeError: a float is required

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